Exhaust fumes

[fixkick]

the top goes on best (new) on a hot day, otherwise not. (rag tops)

the hose on my 91, were turning to SLIM, they were melting. (not from heat just age , stock hoses)

the cat will clean up the stink, but of its running rice hot, if hot. then the cat melts,
so we check AFR first. air fuel ratio and scope the O2 sensor (no OBD2 here) to be sure its runs in closed loop hot.
if not it will be rich in most cases.
the whole system is designed to fail rich,

diagnosing any pre 96 car , (like this) is not easy, lacking scan tools
but is easy with voltmeter,
only the 02 is hard,
the others are all slow moving DC analog signals to see with Voltmeter
the 02 swings about 1vdc and 6 times a second, making only scopes work here. (no obd2)
on this car the top fail is , dead 02. dead 02 heater tops the top.
the 02 stuck at 0v, (exhaust leaks near it)
or The ECU is lost.

what is lost, lost is when (say fuel pressure is at 55psi due to a bad FPR) and ecu can not correct fuel, it a hopeless case like this
but MPG goes to 12mpg and is clearly the first clue but one needs to drive off one full tank fist to notice this big clue.

the tank has many vents (EVAP SYSTEM with lots of hoses) and most tanks rust out. on top,
or tank falls out of car with rusted through mounts.

here off my evap page
here is one collapsing from wrong gas cap (cap missing vacuum breaker valve inside, wrecks 1 tank)
http://www.fixkick.com/sensors/EVAP/wrong-gas-cap1.jpg


take a nice powerful flash light and look above rear tires>

rr

http://www.fixkick.com/INJECTORS/PUMP/pu...tview1.JPG

[GFO4501]

I haven't really checked the tank out yet, although I expect to find some issues since I smell fumes and I've had issues nearly every where else. I did notice someone cut a hole in the floor close to the tailgate and put a patch over it with sheet metal screws. This is on the passenger side and I figured it was done to replace the sending unit or fuel pump without dropping the tank. I would not have done that myself but it will make the job easier I suppose. Would that be in the general area of the pump or sending unit. That's the side you put gas in on mine, not sure about other models. Greg